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Lecture 10

Dr. Mohammed Al-Hazmi

Slide 1

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Mode analysis of a straight bar

Obtain the lowest six vibration modes and resonant frequencies of thestraight steel bar shown in Figure below

Thickness of the bar is 0.005 m, width is 0.01 m, and the length is0.09 m.

Material of the bar is steel with Youngs modulus, E =206 GPa, and =

. .

Density =7.8103 kg/m3.

Slide 2

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5. Set element type

Main Menu: Preprocessor Element type Add/Edit/Delete

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7. Assign material properties

Main Menu: Preprocessor Material Props MaterialModels

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ANSYS Toolbar: SAVE_DB

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9. Create geometry (rectangles)

Main Menu: Preprocessor Modeling Create Areas Rectangles By 2 Corners

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Slide 8

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14. Extrude Bicycle Wrench area Main Menu: Preprocessor Modeling Operate Extrude

by xyz offset

- Select Bicycle wrench area, OK

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Slide 10

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15. Set element size

Main Menu: Preprocessor Meshing Mesh tool

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Slide 12

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17. Analysis type

Main Menu: Solution Analysis Type New Analysis

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Main Menu: Solution Analysis Type analysis Options

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Slide 16

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18. Solve the problem

Main Menu: Solution Solve Current LSa. Click OK on the Solve Current Load Step window

b. Close the /STATUS Command window

c. Close the Solution is done! window

22. Check any warnings or error messages

y enu: e s rror e

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Postprocessing

19. Plot the deformed shape Main Menu: General Post roc Read Results First Set

Main Menu: General Postproc Plot Results Contour Plot Nodal Solu

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Slide 19

Mode 1, 515.043 Hz

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Main Menu: General Postproc Read Results Next Set

Utility Menu: Plot Replot

Slide 22Mode 4, 6920 Hz

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Main Menu: General Postproc Read Results Next Set

Utility Menu: Plot Replot

Slide 23Mode 5, 8778 Hz